Recently, following the development of robot technology, mobile robots, which set the route by themselves and move, have been utilized. In order to allow such mobile robots to effectively determine a position and move in a space, it is required to allow the mobile robot to recognize the position of the robot in the space while generating a map for the space wherein the robot moves.
Mobile robots move by dead reckoning navigation using a gyroscope and an encoder provided in a driving motor, and generate a map by analyzing images taken using a camera provided in the upper portion. In this case, when an error is incurred by the driving information from the gyroscope and the encoder, the image information obtained from the camera is utilized to correct the accumulated error.
However, position-based mobile robots which have been developed until now were developed under the assumption of movement on a two-dimensional plane using a monocular camera or a laser scanner. However, when a monocular camera is used, it is difficult to know the distance to a feature point. Therefore, as the error of the dead reckoning navigation is increased, increasingly many errors may be included in the position recognition results.
Further, since laser scanners are too expensive to be applied to mobile robots, studies for employing a simultaneous localization and mapping (SLAM) technology, which recognizes a space and updates the position using a stereo camera, have been increasing in recent years.
Mobile robots based on SLAM (Simultaneous Localization and Mapping) technology perform the processes of extracting a corner feature point from an image, creating a map by restoring three-dimensional coordinates of the corner feature point, and recognizing a position.
It is very important for mobile robots to recognize a space and recognize their own position in the space. Since mobile robots which do not employ the above-described technique have limited mobility and may provide very limited types of service, mobile robots are being competitively developed.